#include <bits/stdc++.h>
#define se second
#define fi first

using namespace std;


set < int > g[200010], comp;
vector < int > obr;
long long n, m, a, b, dn[200010],ans,xd;
bool used[200010], used1[200010];

void dfs(int v){
    used[v] = true;
    for(auto u: g[v]){
        if(!used[u]){
            dfs(u);
        }
    }
    obr.push_back(v);
}

void dfs1(int v){
    used1[v] = true;
    comp.insert(v);
    for(auto u: g[v]){
        if(!used1[u]){
            dfs1(u);
        }
    }
}

int main(){
    cin >> n >> m;
    for(int i = 1; i <= m; i++){
        cin >> a >> b;
        g[a].insert(b);
    }
    for(int i = 1; i <= n; i++){
        if(!used[i]){
            dfs(i);
        }
    }
   // reverse(obr.begin(), obr.end());
    for(auto x: obr){
       // cout << x << endl;
        if(!used1[x]){
            comp.clear();
            dfs1(x);
            if(comp.size() == 1){
                continue;
            }
            xd = comp.size() * (comp.size() - 1);
            for(auto u: comp){
                xd -= g[u].size();
            }
            ans = max(xd,ans);
        }
    }
    cout << ans;
}